GB1348877A - Electrode assemblies for facsimile recording apparatus - Google Patents

Abstract

1348877 Facsimile recording apparatus ALDEN RESEARCH FOUNDATION 22 March 1972 [1 April 1971 22 Nov 1971] 13420/72 Heading H4F A spiral electrode assembly for a facsimile recorder of the "lawnmower type" includes an electrode 6, Figs. 1, 2, in the form of a flexible strip longitudinally folded to give a contact portion 11 and a flange portion 12 and curved around and secured to the surface of the recording drum 4 by a resilient, tensioned hold-down member 18 attached to the drum at its two ends, and bearing on the flange portion 12 such that the contact portion 11 rises away from the drum surface. The strip 6 is slotted to enable its spiralling and may have cutout tongues 22, Figs. 2, 3, or not, Fig. 5. In the former case the flange portion 12 and tongues fit in a spiral groove in the drum surface, whilst in the latter case the flange portion and part of the contact portion fit in a V- shaped groove in the surface of the drum or in the surface of an intermediate metal or resilient foam strip (Figs. 9, 10, not shown). The ends of the hold-down member are secured by eccentrically mounted screws for easy tensioning (Fig. 8, not shown). The member can be a spring with a loop at one end for engagement by a finger to aid securing. In the embodiments of Figs. 11 to 17 the hold-down member is a strip of resilient material 38, Fig. 17, and is used to hold the strip 36, Figs. 13, 15 down on to a steel band 37, Fig. 12, wound and laid into a helical groove 42, Fig. 11, in the drum surface. The band 37 is tensioned by eccentric screws 40 in the groove turning in holes 50 in the band and is located by pin 41. The stuck out tongues 63 in the strip 36 fit into slits 52 in the band and the hold-down member 38 is pinched between upturned tags 64 on the strip 36 and 53 on the band 37. The line of slits 52 may be non-linear, such that the assembly gives a non-spiral electrode surface.